


UnderTrigger

by somnivagrantTraviatus



Category: Undertale (Video Game), World Trigger
Genre: Gen
Language: English
Status: In-Progress
Published: 2016-03-25
Updated: 2016-04-01
Packaged: 2018-05-29 01:10:41
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 3,248
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6352924
Author URL: https://archiveofourown.org/users/somnivagrantTraviatus/pseuds/somnivagrantTraviatus
Summary: <blockquote class="userstuff">
              <p>On an Earth devastated by attacks from other worlds, only one organization has the ability to protect citizens from the alien threat - the Border Defense Agency, aka Border. When Ebott's division of Border fails to protect the Dreemurr family from being torn apart in the worst way, Frisk, Chara, and Asriel take it upon themselves to fight the Neighbors on their own.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> **Glossary** -
> 
>  **Trion:** A natural energy humans produce from two organs, one in their brain and another in their chest. It circulates like blood throughout the body.  
>  **Side Effect:** A supernatural power possessed by humans with a large amount of Trion.  
>  **Neighbors:** Alien invaders from an alternate dimension adjacent to our own - the "Neighborhood". Neighbors come in different forms, each with their own abilities and names - including the "Humanoid Neighbors", regular humans that just happen to come from the Neighborhood.  
>  **Trigger:** Technology utilizing Trion, typically referring to weapons. Originally from the Neighborhood, but reverse engineered by Border and given to their agents as well.  
>  **Trion Body:** When a Trigger is used, it exchanges its wielder's physical body for one made entirely of Trion. The Trion body is able to take great strain, offensively or defensively. Damage taken to the Trion body does not reflect on the physical body stored within the Trigger, but if too much Trion is lost, the user will revert back to their physical form.

There’s a body lying in the alley, arms and legs already half-covered in snow. The people circulating outside on the street don't pay it any attention, and at first, Frisk thinks that must be because it's dead. But then it moves, chest expanding in a shuddery breath, and Frisk floods with anger at the callousness of humanity.

They take a few deep breaths, moving away from their emotions with the ease of practice - _calm down! Anger never solves anything, child, it is a fire that only burns_ \- and focusing on the task at hand. Gingerly, they reach out, and several things happen all at once:

\- The body’s eyes snap open, red irises latching on to Frisk’s black ones;  
\- A knife buries itself in Frisk’s shoulder;  
\- And Frisk’s hand makes contact with the other person’s arm.

Suddenly, both Frisk and the other person are choking off screams of pain. Something warm drips down Frisk’s back, and they bite down hard on their cheek as the liquid soaks through into their sweater. The pain in their mouth pulls them away from the pain in their shoulder, and, using that as a crutch, they block off the rest of it from their mind. Then they close their eyes, concentrating on filling their soul with compassion, hope, and determination.

When they feel a response, Frisk pulls back a little, and watches as the red fades away from the other’s eyes. When they next blink, the other’s eyes are a brown only a little lighter than Frisk’s, and Frisk smiles.

Anger and fear streak over the other’s face and they pull back, nearly falling over themselves in their scramble to get away. “What is your _deal_?” they hiss, cradling their shoulder close. “Don't you know not to touch strange people?”

With their back against the wall like this, it's easier to see the other person’s tear-stained cheeks. Frisk reaches out a hand to try and touch the other’s face, but a pale hand wraps around their wrist and squeezes threateningly. Taking the hint, Frisk drops their hand and settles back a little further. “...you've been crying,” they remark quietly instead.

Like they aren't even aware of the movement, the other’s hand reaches up to touch a salt-streaked cheek. “No surprise there,” they bite out. “I've only had the worst day in my life, so.” Still, despite their harsh words, something in their face softens. “You really should not have done that,” they say, almost guiltily. “I could have hurt you.”

Sheepishly, Frisk shows them their shoulder. The other person bites back a curse, then pulls back the hand on their own shoulder, frowning in befuddlement when it comes back clean. “Huh? But…”

“That was probably me,” Frisk breathes, with a humorless laugh. “Sorry.”

The other person stares at them. “Did you seriously just apologize for hurting the person who stabbed you?” They huff, a reluctant smile playing over their lips before they turn away, shaking their head. “Get over here, idiot. The least I can do is patch you up a little.”

Frisk nods, regretting the movement when it makes everything spin dizzily. “Frisk,” they say as they shuffle closer. “Not idiot.”

“Yeah?” The other looks up, briefly, from where they're tearing off strips of their green-striped shirt. (That doesn't seem very smart in this weather, but something in the other person’s eyes makes it seem like it would be a bad idea to tell them that.) The silence lingers for a beat too long, and then, gruffly, they say, “Chara.” Under their breath they add, “You are still an idiot, though.”

They aren’t really sure if they were supposed to hear that last bit, but Frisk laughs a little anyway, not denying anything.

Soon, Frisk is lying on their side as Chara kneels over them, bandaging their bleeding shoulder. It's almost a direct reflection of earlier, which makes Frisk smile. They can feel their eyelids drooping as the adrenaline drops away, but Chara’s muttering something important-sounding to themselves about their brother and a funeral, and Frisk doesn't want to interrupt.

They drift to sleep in the snow, Chara’s hands on their back and a smile on their lips as their eyes close.

Elsewhere, another pair of eyes opens. They stare, sightless, at a gray stone ceiling, as their owner realizes that he can't feel a thing.


	2. Chapter 2

**Summary for the Chapter:**

> Chara tells Frisk what happened.

When Frisk wakes up, Chara is curled around them, using their smaller body to protect Frisk from the elements as best they can. Luckily, it stopped snowing overnight, so the two of them are only a little damp, aside from the cold that's seeped its way into their bodies.

As Frisk stirs, Chara rolls off them, red in the face. “It was only to conserve warmth,” they snap. “I could not leave you to freeze alone out here. After… what you did.” Dropping the challenging stare they had been holding, they lower their eyes to grimace at their knees. “I never thanked you for that. So, thanks. I owe you one.”

Frisk shakes their head. “You don't owe me anything,” they insist. “It was just the right thing to do.”

Chara huffs. “Sure, whatever. Anyway, I have to get going.” They start to clamber to their feet, but Frisk’s hand shoots out and grabs an arm, making the paler of the two jump. Chara is about to snap at them, but then they catch a look at their savior’s face and relent a little, gentling their tone. “What do you want?”

“I… could you…” Frisk fidgets, playing with the hem of their stripey sweater. “Stay?”

A sigh tears its way out of Chara's throat. “Look. I am grateful to you and everything, but there is no way I'm letting a clingy stranger make me miss my brother's funeral. You might have saved my life last night, but he did it first, and much more often.” Almost whispering, they add, “It's my fault he's dead in the first place.”

Frisk scoots closer, laying their head on Chara’s shoulder and willing them to feel the compassion Frisk has for them. When Chara flinches at the sudden contact, Frisk breaks the empathic bond - their Side Effect - by moving over to give Chara a little more space. When the brunet looks calmer, Frisk asks, “Tell me about him?”

Chara runs a hand over their face with a ragged sigh, but sits back down against the brick wall, returning Frisk’s bright smile with a quirk of their own lips. “His name was Asriel.” Their eyes dart over to Frisk, listening rapturously, and they say, “He was a lot like I think you might be, actually. Always eager to help others, taking responsibility for anything that might go wrong… A huge crybaby who was fun to tease,” they add, grinning a little as Frisk makes a face. “He wanted to join the Border branch here when he grew up, to help protect Ebott with all of his heroes. Mom and Dad both work at Border, so they taught us how to use Triggers and gave us fighting lessons. Sparring with him was a lot of fun, even if he always let me win.” 

Frisk sidles a little closer. “So, what happened?”

“Neighbors.” A dark shadow passes over Chara’s face, making Frisk shiver a little. “One of them attacked us while our parents weren't home. It was one of those insecty ones, you know, with the sharp legs?”

“A Marmod?” Frisk ventures.

Chara shrugs a little with a snort. “They're Neighbors, so who even cares. The point is, Asriel got it into his head that he needed to protect me, so he took one of the Triggers we were using for practice and went to fight it.”

Frisk winces.

“Yeah,” Chara agrees. “Even worse? He got stage fright. Apparently, fighting Neighbors is harder than Fantomê Squad makes it look on TV, and the idiot couldn't bring himself to hurt the thing.” They shake their head, tears pooling in the corners of their eyes despite their harsh words. “I told him he had to kill it, or he'd die - ‘In this world, it's kill or be killed.’ But he still couldn't do it.” They take a deep breath, then let it out slowly, looking Frisk right in the eye. “It cut his arms off, then slammed him into a wall, Frisk.”

“But, if he was in his Trion body, couldn't he have survived?” Frisk weakly argues.

Chara laughs darkly. “I think the limb loss bled him out. He was definitely in his flesh-and-blood body by the time he hit the wall headfirst.”

“But -”

“Frisk.” Chara looms over them, smile wide. “The crater was bigger than his head.” As Frisk worriedly looks on, Chara’s shoulders begin to shake, and broken laughter begins to roll out of them. “It was- so funny,” they gasp, tears running down their cheeks as they giggle hysterically. “I thought that only happened in cartoons! But no, there’s my brother, and his head hit first and then the rest of his body just kind of hung there for a second, like a plunger arrow or something, a-and then it kind of gave up and went _smack!_ into the wall, and he's just- hanging out there, like he's waiting for his butler dog to put his slippers on! And then his whole body- it just- it _slid down_ , and- and I kept w-waiting for the W-windex noise, but it never came!” Laughter suddenly gone, they shout, “There was only the giant hole in our living room, and my dead brother!” and then collapse into sobs.

Frisk itches to rub Chara’s back, but instead stays by their side, face stoic and eyes squeezed shut. The pain they can feel radiating off Chara is almost too much to bear at this close distance, but this is where they're needed, so they muscle through. When Chara’s finally calmed down a little, they ask quietly, “So what happened next?”

Chara shudders again, and when they raise their head, their eyes are red-rimmed and cold. “It killed my brother. I was _so angry_ … Asriel’s Trigger was right there, so I took it.” Chara turns back to their audience, with their arms wrapped around their legs and their face against their knees. “I'm not weak like he is,” they say flatly, and it's a statement of fact in their mouth. “I killed it and I killed it and I killed it until it disintegrated. I think I broke the Trigger. Then I ran. You know what comes after that.”

“Why’d you run?”

Chara’s mouth opens, then closes. They shake their head. “It doesn't matter.” 

The brunet brushes themself off and pulls themself to their feet. They’re about to take a step toward the mouth of the alley when Frisk, again, brings them to a halt.

“Wait!”

Chara spins around, ready to snarl, but Frisk is standing, hand outstretched. They smile. “Let me come with you?”

Chara eyes the limb doubtfully. “Why should I?”

The other’s smile fades slightly. “Because… I don't think you should be alone right now, Chara,” Frisk answers truthfully. When Chara grimaces, they bow their head. “Also, I want to pay my respects.”

Chara squints at them, looking for any sign that this is a joke, but Frisk’s face stays innocently determined. Finally, Chara sighs. “His body will be at the morgue, for now,” they say. “We should get there soon if we want to see him before the cremation.”

They walk away, Frisk trotting at their heels, and pointedly ignore the pleased smile stretching across the other’s face.


	3. Chapter 3

**Summary for the Chapter:**

> They meet Asriel.

This early in the morning, the morgue is locked, but Chara isn't worried. Pulling out a strip of fabric from one of their boots, they unroll it, select one of the strips of metal within, and jimmy it into the lock. In no time at all, they’ve aligned the tumblers and are opening the door with a click and a dangerous smile. “Please, after you,” they say, motioning Frisk ahead with a courtly gesture.

The building is dark, the early-morning light and gray stone walls not doing much to brighten the atmosphere, and Frisk shivers as they step inside, goosebumps raising on their darker skin as the chill passes right through their sweater. Then Chara joins them, and the door swings shut, leaving the two in darkness.

Chara’s already moving before Frisk’s eyes can adjust. “He’ll be over this way,” they say, voice loud in the still air.

“How do you know?” Frisk calls back, hurrying ahead.

“I just do, okay?” Chara turns and waits for them to catch up, tapping their toes, then leads them through a labyrinth of twists and turns. Finally, they say, “This is it,” and stop in front of the last room.

Chara’s grimacing again, face twisting in an emotion Frisk can't recognize. Before they can ask Chara if they’re okay, though, the brunet huffs a breath and steps through.

This room, somehow, is even colder than the others, or maybe that's just the bodies stacked on the shelves. The corpses are in various states of decrepitude, from the skeleton with rotting clothes at the back of one of the higher shelves to the blond boy staring at the ceiling, green eyes empty. When Chara sees him, a sob tears out of their throat, and they hurl themself at the table. “Oh, Asriel,” they sniffle. “This is all my fault. I told you you shouldn’t have taken me in! Now look at what I've done to you.”

“...Chara?” The voice is scratchy and raw, and, to Frisk’s horror, seems to have come from the body on the table. A green-sleeved hand reaches up, and for a breathless moment, Frisk thinks it’s going to strangle Chara, but it just comes to a rest against their cheek. “Don't blame yourself. You were right; it really is kill or be killed.”

Chara steps out of the contact, breathing hard. “A-asriel?”

The boy on the table gives a strained laugh. “Hiya, Chara. I found out what my Side Effect is.”

Cautiously, Chara takes a step forward. Frisk watches from the doorway, heart in their throat. “Yeah?”

“Yep.” Asriel smiles, but the expression doesn't sit right on his face. “Turns out, I can't die.”

Chara closes the distance between them and throws themself into a tight embrace. With their head pressed into Asriel’s shoulder, Frisk is the only one to see the way the smile drops off Asriel’s face.

Finally, Asriel speaks up. “Hey, Chara?” He waits for their answering hum before continuing. “I'm not… the same. As I was before.”

Chara’s eyes are wary again, hope fighting despair as they give their brother a little space. “How?”

“I can't feel. I can't feel anything.” He laughs, arms spreading wide like he's saying, ‘What can you do?’ Then his expression flattens again, becoming eerily blank. “I thought maybe it would change when you came back, or if I saw Mom and Dad again. But it didn't. When you showed up, I was relieved, but mostly irritated that it took you so long. It didn't make me happy at all.”

Chara doesn't reply. Asriel meets their eyes, then says, deliberately, “I don't think I can feel love anymore, Chara. All I feel is hate.”

From the doorway, Frisk gasps, but Chara just laughs. “Guess that makes two of us.” They take a step forward again, reassuring their brother with their continued proximity. “In this world, Asriel, it's kill or be killed. But if we take the fight to them, we can kill the Neighbors before they kill us. What do you say?”

Asriel’s brow wrinkles. “Are you saying we should join Border?”

“No, idiot, I'm suggesting we take the fight to them ourselves. Who needs a bunch of idiots telling us what to do? All we need are some Triggers, and we can start paying the Neighbors back for what they did to you.”

“To us,” Asriel corrects, turning over the idea. “But… What about Mom and Dad? Shouldn't we tell them we’re okay?”

Chara sighs, laying a gentle hand on their brother’s shoulder. “Look, Asriel. You know as well as I do that they would never let us do this. Besides, it's sad, but they think we’re dead. It would be so much easier to just let them keep on thinking that, instead of having to deal with trying to convince them that we’re really back.”

He frowns at that, but acquiesces with a sigh. “Yeah, you're right.”

“Just like always,” Chara teases, making him smile.

“Guess so.” He turns to the doorway. Frisk gasps and ducks out of sight, but Asriel just rolls his eyes. “Are they coming, too?”

Chara shrugs. “Hey, Frisk,” they call. “Do you want to help us kill some Neighbors?”

There’s a pause. Finally, the answer comes wafting back. “I don't like the idea of killing,” says Frisk quietly. “I think that everyone can be good if they try, so, no matter how bad something is, it deserves a chance to live. But, the… the Neighbors… All they've done is kill. If we want them to stop hurting people, we have to make them stop. If you'll let me, I'm in.”

Asriel rolls his eyes. “Do you even know how to use a Trigger?”

“Yes,” comes the answer, soft but assured.

Taken aback, Asriel glances at his sibling. Chara helps him sit up, and then the two confer silently. Finally, Chara nods. They stand and walk outside, to where Frisk is huddled against the wall, and offer them a hand. “Welcome to the team.”

Smiling shyly, Frisk lets Chara help them to their feet. “Thanks.”

“For the invite, or the lift?” Chara looks down pointedly at their hands, which are still twined together, and Frisk drops it with a blush.

“Both.”

Chara smiles. Then they wave Asriel over, and glare at him until he extends a hand, too.

“I’m Asriel.”

“Frisk.” Frisk reaches out, gingerly, and takes the hand. Judging by the look on their face, he squeezed it, but, judging by his quiet yelp, they squeezed right back. Asriel backs away, rubbing his hand, and Frisk grins. “Sorry, did I hurt you?” they ask, apology sincere despite their amusement. “I don't like fighting, but that doesn't mean I'm weak.”

“No, I'm fine,” Asriel grumbles, impressed despite himself. Then he says, “If we’re going to be working together, we should be on friendly terms. But if you do anything to hurt Chara, we won't be so friendly anymore.”

Chara rolls their eyes and nudges him. “I can make my own threats, Asriel. I don't need you to protect me. Besides, Frisk already saved my life today. It would be pretty stupid of them to do that, just to try killing me afterwards. And anyway, if that little display was anything to go by, I don't think you're in much of a position to be making threats.”

Asriel deflates a little, and Chara takes pity on him. “Come on, you two. People could show up any minute. We should find somewhere out of the way to hole up and make plans.”

Asriel falls into step immediately, familiar with his sibling’s movements, but Frisk takes a little longer to scramble up and join them. “Our old treehouse would be perfect for that,” the blond notes, at the same time as Frisk asks, “What plans?”

“Plans like team names, who is going to be the leader, and how we are going to obtain three Triggers,” Chara answers. “And, Asriel? The treehouse idea sounds perfect.”


End file.
